A 1975 study, confirmed by another one in 2001, found a high positive correlation between class attendance and course grades at the law school level. A study by the author of this article sought to confirm the findings. In third-year courses taught at three law schools, grades earned by students with perfect attendance were compared with grades earned by students whose absenteeism triggered a warning letter. The results confirmed existence of a strong positive correlation between class attendance and grades. Attendance (or non-attendance) affected grades by an average of almost half a grade level.